This invention relates to electric circuit interrupting devices, and more specifically to circuit interrupting gas discharge tubes, and circuit arrangements incorporating the same.
One example of gas discharge tube which may be used as a circuit interrupting gas discharge device is a thyratron, that is to say an electronic tube having within an envelope containing a gas or vapour filling, an anode and a cathode and at least one control grid between said anode and cathode.
It is desirable, particularly when said thyratron is utilised as a circuit protection device, for quenching to be effected rapidly.
It is known, from our prior United Kingdom specification No. 1,494,051, for example, to arrange form means for producing a magnetic field in the region of the discharge, and extending transversely thereto, to effect quenching. Such a technique is inconvenient however.
One technique which might be thought to be simple and attractive in order to effect quenching by an electrostatic effect, is to apply a negative potential to a control grid to which previously a positive potential had been applied in order to initiate discharge. However, it has been found that such a technique with thyratron tubes as at present known is unsatisfactory.